JP2001089612A - Pigment for warpage-free polyolefin coloration - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the use of a pigment for the coloration of polyolefins which do not warp. SOLUTION: A pigment of formula I (wherein X is Cl or CH3) and of formula II (wherein R is phenyl or C12H25) is used for the coloration of polyolefins which do not warp.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to the use of pigments for warp-free coloring of polyolefins.

[0002]

BACKGROUND OF THE INVENTION When using organic pigments to color polyolefins, especially high density polyethylene, unexpected shrinkage and warpage problems can occur. This may be due to a change in the crystallization behavior due to the presence of the pigment. Some studies have shown that the pigment acting as a nucleating agent affects both crystallite size and crystallization rate, causing crystallization at higher than expected temperatures.

[0003] All of these points have significant commercial problems. For example, the coloring of bottle crate is a very important market for pigment manufacturers. Pigments must fulfill an important condition when used in high density polyethylene applications, which must not affect the crystallization process of the polymer. Such effects can cause shrinkage and warpage, which can deform the injected article and reduce its mechanical properties.

[0004]

When using organic pigments for coloring polyolefins, surface treatments have been developed for the purpose of modifying the pigment surface in order to avoid this problem. By depositing a thin layer of metal oxide (eg, zirconium, silicon, aluminum) on the surface of the organic particles, or by adsorbing or precipitating some polar polymer (polyacrylate or cellulose derivative) on the surface of the pigment. is there. However, these processes are not always effective.

[0005]

Accordingly, there is provided a thiazine-indigo pigment of the formula (I) or (II),

[0006]

Embedded image In the above formula, X represents Cl or CH ₃ ,

[0007]

Embedded image Wherein R is phenyl or C ₁₂ H ₂₅
It has been found that it does not cause warpage when used in high density polyethylene.

Other derivatives of this group, for example of the formula (II)
The two pigments I) and (IV) and the pigments of the formula (II) where R = p-C ₆ H ₄ CF ₃ were also tested, but these were used when used in high density polyethylene. Shows warpage.

[0009]

Embedded image

[0010]

Embedded image

Accordingly, the present invention resides in the use of the pigments of formula (I) or (II) for the coloring of non-curled polyolefins, and the use of pigments of the formula (I) or (II) A polyolefin, more preferably high density polyethylene (HDPE).

When coloring polyolefins with the pigments of the formula (I), they are used in customary amounts, ie from 0.01 to 30% by weight, preferably from 0.1 to 10% by weight, based on the material to be colored. Any quantity can be used.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The test method is described below.

Injection molded 60 × 6 with HDPE containing 0.1% pigment and HDPE without 0.1% pigment
10 test plates of 0 mm.

Processing temperatures are 220 ° C and 280 ° C.

Results: Difference in length and width measurements between test plates with unpigmented HDPE and test plates with HDPE pigmented with 0.1% pigment.

% FV = (% vertical shrinkage−% horizontal shrinkage) /
(Horizontal shrinkage) × 100%% FV = 0 to 10%: good% FV = 10 to 20%: suitable% FV> 20%: unsuitable

[0018]

[Table 1]

With the pigments of formulas (I) and (II), excellent results were obtained with respect to the warpage of the test plates.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Banj Lal Kaul Switzerland, Twe Her 4105 Beer-Benken, Brutskákasjäutlasse 48 (72) Inventor Briyuno Piastre France, F-68330 UNING, Liu Laboisier 12

Claims (3)

[Claims] 1. A pigment of the formula (I) for the coloration of non-warped polyolefins, A pigment wherein X represents Cl or CH ₃ ,
A pigment of the formula Use of the pigment R is phenyl or _C 12 _{H 25} in the above equation. 2. A pigment of the formula (I), which comprises A pigment in which X represents Cl or CH ₃ , or a compound of the formula (I
The pigment of I), which is A non-warped polyolefin colored with a pigment wherein R is phenyl or C ₁₂ H ₂₅ in the above formula. 3. A pigment of the formula (I), wherein A pigment in which X represents Cl or CH ₃ , or a compound of the formula (I
The pigment of I), which is R in the above formula is pigmented is phenyl or _C 12 _{H 25,} warp not high-density polyethylene (HDPE).